Hydrocarbon Prospectivity and Risk Assessment of “Bob” Field Central Swamp Depobelt, Onshore Niger Delta Basin, Nigeria

Abstract

This paper evaluates the hydrocarbon prospectivity and play risks of “Bob” field in Niger Delta Basin, Nigeria. The aim is to enhance exploration success through improved approach/technique by incorporating risk analysis that previous studies have not fully considered. This approach combines a set of analyses including stratigraphic/structural, amplitude, petrophysical parameter, volumetric and play risk using a suite of well logs and 3D seismic data. Maximum amplitude anomaly map extracted on the surfaces of delineated 3 reservoirs revealed 6 prospects, namely: Dippers, Cranes, Turacos, Nicators, Jacanas and Pelicans with hydrocarbon accumulation. Petrophysical analysis showed ranges of values for porosity, permeability and water saturation of 0.21 to 0.23, 158.96 to 882.39 mD, and 0.07 to 0.11, respectively. The various prospects yielded the following stock tank volumes 12.73, 6.84, 3.84, 11.32, 7.42 and 4.76 Million barrels (Mbls) each respectively in a column of 66 ft reservoir sand in the study area. Play risk analysis results gave: Pelicans and Nicators (low), Turacos and Dippers (moderate), while Jacanas and Cranes show high risk with minimal promise for good oil accumulation. The prospects possess good reservoir petrophysical properties with low to moderate risk, thus, viable for commercial hydrocarbon production, which increases confidence in management decisions for production.